Method of heating oils



June 2, 1931. DE FLOREZ METHOD OF HEATING OILS 2 Sheets-Sheet f1 rialFiled July 2, 192: v

n gwue tto'c J1me 1931- 1.. DE FLOREZ METHOD OF HEATING OILS 2Sheets-Sheet 2 Original Filed July 2, 1926 an tot a m Patented June 2,1931 UNITED STATES PATENT; OFFICE LUIS mi I'LOBEZ,

OF POMFRET, CONNECTTCUT, ASSIGNOB TO THE TEXAS COMPANY, OF

, NEW YORK, N. Y., A CORPORATION 01' DELAWARE IETHOD OI HEATING OILSOriginal application filed m 2, 1920,

- My invention relates to a method of heatradiant andconvection heatineffects in or- In der to avoid the injurious e ects of localoverheating, and several means for obtaining this result have beenproposed. So far as am aware, however, none of the proposed methodsresult in a complete or substantial- 1y complete separation, andrecourse is had to such expedients as shielding the tubes by arefractory'substance or the like in order to avoid the effects of heattransfer by convection.

In the apparatus suitable for carrying out my invention, 1 secure asubstantially complete separation of the radiant and convection heatwithout resort to the interposition of a refractory shield or the likebetween the so source of heat and the tubes, the source of heat and thetubes being at all times in open communication. The nature of myapparatus furthermore, permits of an arrangement such that sagging ofthe tubes from the effects of heat is avoided, the tubes are readilyremovable for cleanin and. the structure of the furnace is greatly ceapened andsimplified.

' This application is a division of my copending application, Serial No.120,067, now U. S. Patent 1,717 ,834, improvement in furnaces, filedJuly 2, 1926- The preferredlembodiment of apparatus suitable forcarrying out my invention consists of a furnace having two sections, acombustion chamber of substantially uniform cross section rovided withtubes to absorb the heat of ra iation onl and an economizer sectionwhere the pro nets of combustion come into direct contact with a bank ofheating fluids in tubular heaters and has special Serial No. 120,067.Divided and this application filed April 17, 1929. lerial No. 355,754. I

ing elements placed in their path. I preferably construct my combustionchamber in cylindrical form, disposing the tubes vertically and suporting them from an up er tube sheet an arranging them so that tl ieyvirtually line the inner surface of the com.- bustion chamber. Theproducts of combustion pass vertically through the center of thecombustion chamber in a direction generally parallel to the plane of thetubes, radiating heat to the vertically disposed tubes but nottransferring any substantial amount of heat thereto by contact since thebulk of the gases will not come in contact with them and the atmosphereimmediately surrounding the tubes is substantially out of the flowingcurrent of the products of combustion. thermore, the section of thepassage through which the products of combustion flow is maintainedsubstantially constant which tends to avoid turbulences in flow whichmight throw the hot ases against the tubes. The gases, havin ra iatedheat to the vertical elements an consequently been reduced intemperature, then pass into the economizer section at such a temperatureas to be substantially non-radiant. The hot gases here come in contactwith and flow around a second group of heat'absorbing tubes which arethus consequently adapted to absorb the con; vection component of theheat.

A feature of the invention is the annular arrangement of heat absorbingtubes within the combustion chamber permitting the flaming gases to passvertically through the annular space formed'by the tubes withoutimpinging on the surfaces of the tubes, thus avoiding the necessity ofshielding the tubes as heretofore practiced, such as, for instance,imbedding them in the wall and roof of the combustion chamber, orincasing them in heat resisting material.

When the vertically disposed tubes are arranged circularlyabout thesource of heat and the path of the heated gases they form a protectivelining or shield for the walls of the furnace, which consequently may beof lighter construction, and less heat will be lost by radiation throughthe walls, as they receive only a portion of the heat imparted to themin existing furnace designs.

The invention also provides other novel arrangements, such as a simplemethod of supporting the tubes, whereby they may be readil removed forrenewal and accessible from 0th ends for cleaning.

The invention will best be understood if the following description isread in connection with the accompanying drawings, in which Figure 1 isa side elevation partially in section of a furnace according to myinvention, showing a bottom-fired combustion chamber connected to aneconomizer section and the manner of vertically disposing the tubes inthe combustion chamber;

Figure 2 is a detail plan view on a reduced scale of the upper tubesheet of the combustion chamber shown in Figure 1;

Figure 3 is a detail view showing the manner of mounting the tubes inthe combustion chamber as shown in Figure 1;

the line 7-7 of igure 5, showing the manner in which the tube endsareconnected; and

Figure 8 is a detail plan view of the upper tube sheet of the combustionchamber shown in Figure 5.

In the embodiment of my invention shown in Figures 1 to 4, 10 representsa'cylindrical combustion chamber built of brick work or other suitablematerial which may be held in shape'merely by the circular bands 11. Itwill be understood that the combustion chamber may equally well be madesomewhat conical or chimney-like in shape, and that this constructionmay be desirable with a hi h furnace as an aid to structural stabilityor or a the purpose of modifying the section to allow for the change involume of the products of combustion to maintain uniformity of flow. Atthe bottom of the combustion chamber a burner 12 or other source of heatis located inside the fire box 13, the sides of which extend well abovethe burner. At the top of the combustion chamber, and extending downinto the chamber isa are or passageway 14 connecting the combustionchamber with the economizer section 15, in. which is located a bank oftubes 16 preferably ositioned horizontally at right angles to t e pathof the heated gases thercthrough. Circularly arranged within thecombustion chamber 10 adjacent the side wall but not in contacttherewith are the vertically dis osed tubes 17 supported from an uppertu e sheet 18. The tubes so arranged form a surface virtuall lining theside wall of the furnace and sliielding it from the intense heat towhich combustion chamber walls are ordinarily subjected. As shown inFigure 1, the tubes 17 extend well above the lower end of the flue 14and below the top of the fire box 13. The hot products of combustionflowing up from the urner '12 pass through the center of the furnace,radiating heat to the annularly arranged tubes 17 but not transferringany substantial amount of heat to the tubes by contact since the tubesare situated out of the ath of the gases.

T e tops of the tubes extend through apertures 19 in the tube sheet 18and the lower ends project into an annular casting 20 extending aroundthe firebox, which holds the tubes in place and spaces them evenly inrelation to one another. The casting 20 serves the function of a lowertube sheet, and is preferably formed in a plurality of arcuate sectionsopen along their outer wall, as shown in Figure 4. Each section may beprovided near each end with a strut 21, placed in such position that itwill not interfere with the access to the tube headers. The tubes assthrough apertures in the upper surface 0 the casting 20 into the chamberthus provided. The tubes are connected together in series by headers 22located at their ends as shown in Figure 3. Ready access may be had toeither end of the tubes by means of plugs 23 in the headers 22 forcleaning or otherwise.

As is usual in heating apparatus of this type, the oil or other liquidto be heated flows first through the tubes 16 of the economizer section15 and then through the tubes 17 of the combustion chamber 10.Preferably the oil in the economizer section flows counter-' current tothe flow of the products of combustion, entering the lowest tube 16 ofthe economizer section and flowing upwardly through the tubes 16connected in'series, the final tube 16 being connected to the upper endof one of the tubes 17 in the combustion chamber 10. The alternate endsof the tubes 17 are connected by headers as shown in Figure 3, and theheated oil or other liquid flows downwardly through the first tube 17,then trance of the. flame into these corners and consequent erosion ofthe tubes at these points. These shoulders also serve to keep the flamesomewhat centered and away from the combustion chamber 25 is fired fromthe top by a burner 26. In this modification the connecting flue 27 islocated below the combustion chamber and the, economizer28, and it ispossible to support the tubes in the combustion chamber in such a mannerthat when in need of cleaning, a tube ma be readily removed and a cleantube substituted, thus reducing the idle time of the equipment. In

order to accom lish this a somewhat different construction 0 the tubesis used. A number. of U-shaped tubes 30 are arran ed in the combustionchamber as before, an are supported from an upper tube sheet 31, whichis provided with slots 32 as shown, in Figure 8, to

permit the U-tubes to be inserted therethrough. A separate flame plate33 is placed over each slot 32 and supported on the top of the tubeplate 31, and is rovided with'two apertures to accommodate the ends ofthe tube 30. The U-tubes 30 are connected together byreturn bends 34which are joined to the tubes by unions 35. In this manner the tubes areheld in place only by their own weight and are free to expand orcontract as they vary in temperature.

A furnace constructed in accordance with my invention eflectuallydistributes the work done by the heating surfaces and to a large extentreduces the ossibility of over-heating of elements whic would bedetrimental either to the surfaces thus attacked or to the fluid beingheated and flowing within the tubes. As will be seen, this isaccomplished by absorbing heat by radiation from the flame until theproducts of combustion have been so reduced in temperature that they canbe safely put into contact with the usual form of heating elements. Itis, of course, desirable to burn fuel with the least amount of excessair possible, which always results in the first contact elements is thusreduced to a safe limit, at the same time permitting efficientcombustion of the fuel without the necessity of admittin excess air.

By disposing the tu es vertically, it will be noted that the section atright angles to the ath of the hot gases is substantially uniorm,tending to permit a smooth flow and to avoid the forming of -,eddiesaround the.

tubes which would cause a transfer of heat by contact. If the tubes weredisposed horizontally around the path of the flame, the difference inthe area of sections, taken between the tubes and through the tubes,would tend to cause a turbulence in the flow of the 'hot gases which isundesirable for the above reasons. Thus, the disposing of tubesvertically not only adds to the structural merit of the furnace byavoiding sagging of the tubes, but is an important factor in eliminatingheat transfer by contact with the radiant heat elements.

'The circular form of the combustion-chamher and the shielding of thewall by the heat elements reduces the costs of construction by utilizinga stable form of structure and permitting the use of lighter walls.

The steel work required to hold the combustion chamber together islargely reduced over furnaces of rectangular sections and the necessityof using arches and roof sections is avoided;

It will be obvious that changes -can be made in the design and'that thecombustion chamber can be built rectangular in cross section withoutdeparting from my invention, although the' combustion chamber ispreferably made circular in form for the above reasons and this circularform is distinctly an improvement on the existing practice.

In the invention shown by the drawings, one row of tubes has beenindicated in the combustion chamber. This, however,is pri-' marily forthe purpose of illustration and I contemplate, when necessary, using twoor more rows, preferably in staggered relation- V ship, which may bedesirable to absorb as Y much of the radiant heat as possible, and

furthermore, the combustion chamber and the economizer sections may beconstructed one above-the other if desired, although the indicatedarrangement is preferred for structural reasons.

What I claim is:

1. The method of quickly raising oil to a desired temperature, whichcomprises burn-' ing a fuel to create a flame as a source of'intensiveradiant heat and 'impelling the flame and the products of combustion ina vertical unobstructed path, and passing the oil in radiative relationto the flame and the hot combustion roducts serially through verticalpaths whlcli are parallel to the pathof the flame and productsofcombustion and substantially equidistant therefrom, to quickly absorbradiant heat and reduce the temperature of the products of combustion,while maintainin r the products of combustion in subitantialfynon-convective relation to said at s. p 2. The method of heating amedium to a desired temperature, which comprises burning a fuel tocreate a flame as a source of intensive radiant heat and impelling theflame and the products of combustion in a vertical unobstructed path,and passing the medium in radiative relation to the flame and the hotcombustion products serially through vertical paths which are parallelto the path of the flame and products of combustion and substantiallyequidistant therefrom, to quickly absorb radiant heat and reduce thetemperature of the products of combustion, while maintaining theproducts of combustion in substantially non-convective relation to saidpaths.

In witness whereof I have hereunto set my hand this 1st day of April,1929.

LUIS DE FLOREZ.

